Question

代码：

<Button Style="{StaticResource HPForegroundStyle}" IsTabStop="False"                 
        Command="{Binding ForegroundPhoneCommand}"  Click="Button_Click">
                    <Button.ContextMenu>                   
                        <ContextMenu ItemsSource="{Binding OptionsMenuItemList}"                            ItemContainerStyle="{StaticResource ContextMenuItemStyle}" 
                                     IsOpen="{Binding IsMenuOpen}"                                        
                                     PlacementTarget="{Binding RelativeSourc={RelativeSource AncestorType={x:Type Button}}}">
                        </ContextMenu>
                    </Button.ContextMenu>
    </Button>

我正在使用MVVM模式。在ViewModel中，我有一个属性'IsMenuOpen'，它控制上下文菜单打开关闭。问题是我能够禁用右键单击而不能在左键单击时显示上下文菜单。

Answer 1

您还可以检查父控件上的ContextMenuService.IsEnabled附加属性。它将仅阻止右键单击，您仍然可以在左键单击时手动显示菜单，因此基于前面的示例：

<Button x:Name="btn" Click="btn_Click" ContextMenuService.IsEnabled="false">
    <Button.ContextMenu>
        <ContextMenu x:Name="popup">
         ...
        </ContextMenu>
    </Button.ContextMenu>
</Button>

private void btn_Click(object sender, RoutedEventArgs e)
{
    popup.Visibility = Visibility.Visible;
    popup.IsOpen = true;
}

Answer 2

这对我来说使用类似于问题的XAML。

private bool _isMenuOpen = false;
public bool IsMenuOpen 
{
    get { return _isMenuOpen; }
    set 
    {
        // Don't allow the UI (right-click) to set this property to true
        if (!value)
            _isMenuOpen = value;
    }
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    Button btn = sender as Button;
    _isMenuOpen = true;
    btn.ContextMenu.IsOpen = true;
}

Answer 3

要跟踪的一些事情：

确保ContextMenu的DataContext有效。
确保IsOpen是双向绑定。
如果您要尝试左键单击打开，请记住PlacementTarget无效，因此您必须设置Button.ContextMenu.PlacementTarget = this，然后设置IsMenuOpen = true才能显示它。

我的代码段供参考：

<Style x:Key="SubjectButtonStyle" TargetType="{x:Type Button}" BasedOn="{StaticResource CommandButtonStyle}">
<Setter Property="Foreground" Value="Green" />
<Setter Property="ContextMenu">
    <Setter.Value>
        <ContextMenu DataContext="{Binding PlacementTarget.DataContext.Manager, RelativeSource={RelativeSource Self}}" 
                     ItemsSource="{Binding SubjectManager.ContextMenuItems}"
                     IsOpen="{Binding SubjectManager.ContextMenuIsOpen, Mode=TwoWay}">
            <ContextMenu.ItemContainerStyle>
                <Style TargetType="MenuItem">
                    <Setter Property="Command" Value="{Binding OnClick}" />
                </Style>
            </ContextMenu.ItemContainerStyle>
        </ContextMenu>
    </Setter.Value>
</Setter>
<Style.Triggers>
    <Trigger Property="IsMouseOver" Value="True">
        <Setter Property="Foreground" Value="DarkGreen" />
    </Trigger>
</Style.Triggers>
</Style>

在视图模型中：

public void ShowContextMenu(SearchCondition searchCondition, Button button)
{
    button.ContextMenu.DataContext = this;
    SubjectManager.OpenContextMenu();
}

Answer 4

如果要将菜单绑定到属性，请考虑使用Popup控件。它具有与上下文菜单类似的功能，但未绑定到特定的鼠标按钮...

<Popup IsVisible = {Binding IsMenuOpen} >
    <!-- Fill in what you need here -->
</Popup>

Answer 5

你可以这样做：

<Button x:Name="btn" Click="btn_Click" MouseRightButtonDown="btn_MouseRightButtonDown">
    <Button.ContextMenu>
        <ContextMenu x:Name="popup" Visibility="Collapsed">
            <MenuItem Header="aaa"></MenuItem>
            <MenuItem Header="bbb"></MenuItem>
        </ContextMenu>
    </Button.ContextMenu>
</Button>

private void btn_Click(object sender, RoutedEventArgs e)
{
    popup.Visibility = Visibility.Visible;
    popup.IsOpen = true;
}

private void btn_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
    popup.Visibility = Visibility.Collapsed;
}

禁用右键单击并使用MVVM在WPF中启用左键单击上下文菜单

5 个答案: